Thermo-treatment or controlled pyralysis of wood is the process that allows heat to act on the cellular structure of the wood, in such a way as to offer a stable, sutured and weather-resistant material. The treatment process using temperature and water vapor makes it possible to obtain thermally modified wood (thermowood) with the optimal characteristics for each process. In fact, the control of the procedure makes it possible to give the wooden boards the desired qualities.
How wood heat treatment is done
The first phase of the treatment involves reaching a level of internal humidity in the solid of 0%, subjecting it to temperatures close to 100 degrees. The times required may vary according to the wood species and the thickness of the boards.
Subsequently we proceed to the drying phase, in which the wood is exposed to a suitable temperature to guarantee a chemical change. In this part of the process the sugars present in the cells undergo a mutation and stabilize the shape of the cell itself. The loss of resin therefore has a dual function: on the one hand the board decreases in weight by increasing its rigidity and on the other it loses those sugary substances which could make it particularly “attractive” for fungi and bacteria.
The high temperatures in which all this happens could generate fires in the boards, and this is why this treatment is performed in the absence of oxygen (with the vacuum method).
After having acted with the treatment at high temperatures (a process that lasts an average of 5 hours), stabilization is carried out, gradually decreasing the internal heat until it reaches room temperature. At the same time, action is taken to restore the ideal amount of humidity to the wooden boards for subsequent processing.
How the vacuum treatment of wood was born
Vacuum heat treatment is the result of studies carried out with dedication by the Pagnozzi family. It was precisely the engineer Vincenzo Pagnozzi who, way back in 1962, created the first industrial prototype in the world for vacuum drying wood. More than sixty years have passed, in which the son and grandson of the engineer Pagnozzi have continued, with the same dedication and passion, the path aimed at providing companies in the sector with the best products for treating wood. Today WDE Maspell is an Italian company known and appreciated all over the world.
